Hi! I just finished this same lesson so I don't have much knowledge to give you a critique, your work is very detailed and your constructions seem 100% solid to me, I'd say you're ready to move on. Nitpicking for the feedback, I'd say some of your thicker lines, even though they seem to be stylistic choices, are kinda flattening your drawings a little bit, specially when you use extra thick lines in the whole extension of the part of the drawing that is close to the floor. This is very visible in your organic intersections, the shadows of the base wouldn't be straight in the front like you did, the same happens to your Pallas Cat of the top right corner on page 1 and to the bigger one in page 2, as well as the frog and the lizard.

And nitpicking again, a lot of the legs you did look a bit stiff, I think the major cause for this is caused by their proportions, the segments have sizes pretty close to each other, both in height and width. Overall amazing working, good luck on your journey :)